This invention relates generally to surgical instruments and, more particularly, to surgical clamps for use in the suturing of elongated vessels.
Surgical instruments of this particular type are useful in the approximation of elongated tubular vessels, especially the vas deferens, the fallopian tubes and blood vessels, during surgical anastomosis, and, additionally, in the surgical suturing of fibers, such as nerves and nerve bundles. An instrument of this type typically includes two clamps, each for gripping a separate one of the vessels to be sutured, along with support means for controllably moving the two clamps towards each other, to "approximate" the respective ends of the vessels.
A popular technique for the anastomosis of the vas deferens, i.e., vasectomy reversal or vasovasostomy, was developed by Sherman J. Silber, M.D. and is described in an article written by Silber entitled "Microsurgery in Clinical Urology", appearing in Urology, Vol. VI, No. 2, pp. 150-53, August, 1975. After suitable initial preparation of the two vas segments to be joined together, each of the segments is gripped securely by a separate one of the two clamps of the approximation instrument and the clamps are controllably moved together to approximate the end of the two segments. A plurality of mucosal stitches around the vas lumens are then made, followed by a plurality of adventitia stitches around the periphery of the vas, to secure the two segments together. Since the size of the vas lumens is exceedingly small relative to the size of the vas deferens, itself, it is critical that the approximation instrument maintain the two vas segments in a precise axial alignment during the operation.
Prior approximation instruments, however, have not proven entirely satisfactory for use in vasovasostomy surgery of type described above. One typical approximation instrument of the prior art includes two clamps in the form of spring-loaded clips, each for gripping a separate one of the two vas segments to be joined together. A first clamp is coupled to a stable base member and a second clamp is coupled to a rotatable lead screw, whereby rotation of the screw causes the second clamp to be moved toward the first, to approximate the two vas segments. The instrument has not proven entirely satisfactory, however, primarily because the spring-clip clamps offer little resistance to the movement of the vas segments out of axial alignment with respect to each other. Additionally, the spring clips ordinarily cause a significant deformation of the segments, and, since only one of the two clips is movable relative to the base of the instrument, an undesirable stress on the corresponding vas segment can result when the segments are being approximated. As a result of these drawbacks, excessive time is ordinarily required to complete the surgical suturing of the segments.
Other known approximation instruments for use in vasovasostomy surgery utilize clamps that have resilient linings and that are held together by friction. These instruments, likewise, have not been found effective in maintaining a precise alignment of the vas segments to be joined. As a result, excessive time is required to complete a surgical vasovasostomy.
Other approximation instruments, for particular use in the anastomosis of blood vessels, are disclosed in Canadian Pat. No. 618,821, issued to C.A Reindorf and entitled "Surgical Clamp", and in U.S. Pat. No. 3,561,448, issued to K. Peternel and entitled "Blood Vessel Suturing Apparatus". Both prior patents disclose approximation apparatus having a pair of clamps mounted on the ends of arms that are pivotally connected to each other. The apparatus disclosed by Reindorf includes clamps in the form of spring-loaded clips, similar to the spring-loaded clips of the vasovasostomy instrument described above, and thus it is susceptible to many of the same drawbacks. The instrument disclosed in the Peternel patent includes clamps that have cylindrical seats for conformably receiving the vessels to be sutured together and holding them in place by means of air suction. Although the vessels are inhibited from moving relative to the clamps, the pivotal arrangement of the clamps allows the vessels to be positioned in axial alignment with each other only when they are in actual abutment. Moreover, the pressure with which each clamp grips the corresponding vessel is not controllable, and the clamps are not readily adaptable for use with vessels of varying sizes. Additionally, the bulkiness of the instrument can sometimes interfere with the suturing of the vessels.
It will be appreciated from the foregoing that there is a definite need for a surgical instrument for use in the approximation of elongated vessels and fibers during surgical anastomosis, wherein the vessels are gripped with a controllable pressure, without being significantly deformed, and wherein the vessels are maintained in a precise axial alignment throughout the approximation procedure, thereby facilitating a rapid suturing of the vessels. The present invention fulfill this need